How to make your documents and designs more readable

White Space

White space is far more attractive than increased size of letters. The greater the amount of whitespace, the greater the number of readers that will pay attention to the ad. Improvements in the distribution of whitespace increase ease of reading more than improvements in writing style.

Copy

Make your copy shorter. The average person spends 10 seconds looking at an ad and will read less than 10 percent of the ad. The percentage decreases with the amount of words on a page. The more words on a page, the fewer words a person reads.

Value & Color

Black type is most legible against a paper with a yellowishtone. Bright white papers are not easy to read.

Type set white on black is 15% more difficult to read than type set black on white.

3/4 of all readers prefer black on white

If reversed type or white type on a solid background (color or black and white) is specified, it should be no smaller than 12 points. It's better to switch to a heavy or bolder weight to make the type more readable.

Typography

The majority of readers confronted with good typography and bad typography recognized bad typography immediately.

Serif typefaces are slightly more legible than sans-serifs for long body copy. Serifs increase both legibility and recognition. 2/3 of readers favor serif typefaces.

Serif typefaces should not be specified for television or the web unless they have been custom made for that purpose. On a monitor or television, serifs are actually less legible than san serifs.

The most legible typesizes for text weights are between 9-12 points. The optimal size depends on the x-height of the typeface.

When working with very tight spaces, a typeface with a higher x-height in comparison to it's point size will yield better readability.

Spacing

Paragraphs set with a slight indentation (2-3 em) are easier to read than paragraphs without indentation.

Spacing within paragraphs also increases readability and can be a substitute for indentation. (I prefer additional paragraph spacing rather than indentation)

Kerning that is visually proportional to the letter's width affords then highest degree of legibility.

Lowercase letters are much more legible than uppercase letters. There is no difference in legibility between headlines set in all lowercase and those set in Uppercase/Lowercase.

Display lines set in all capital letters are difficult to read. Body copy set in all caps is totally illegible.

Words set in all caps are read letter by letter. Reading is approximately 15% slower in words set in all caps.

Variations

Condensed or expanded letters are not as legible as normal width letters

Medium or normal variations are more legible than boldface or light variations

Regular versions are more legible than italics, bold, condensed or expanded type

Boldface is a much better choice for emphasis than italics. However too much bold on a page tires the reader.